Solve for $x$ and $y$ using substitution. ${3x-6y = -12}$ ${x = -y-1}$
Answer: Since $x$ has already been solved for, substitute $-y-1$ for $x$ in the first equation. ${3}{(-y-1)}{- 6y = -12}$ Simplify and solve for $y$ $-3y-3 - 6y = -12$ $-9y-3 = -12$ $-9y-3{+3} = -12{+3}$ $-9y = -9$ $\dfrac{-9y}{{-9}} = \dfrac{-9}{{-9}}$ ${y = 1}$ Now that you know ${y = 1}$ , plug it back into $\thinspace {x = -y-1}\thinspace$ to find $x$ ${x = -}{(1)}{ - 1}$ $x = -1 - 1$ ${x = -2}$ You can also plug ${y = 1}$ into $\thinspace {3x-6y = -12}\thinspace$ and get the same answer for $x$ : ${3x - 6}{(1)}{= -12}$ ${x = -2}$